Rock-type units from USGS
Here’s a geology map for field navigation in more accessible portions of the Greater Chilkat Watershed—US side only. This geopdf is an interim product, to be updated as we ground-truth it.
My draft chapter in the GCW Atlas gives background on rock types, faults, geologic terranes, etc. My adaptation for geopdf preserves the code abbreviations shown here, adding brief list of the unit’s dominant rocks, and a field for time-period: capital letters in these codes.
My surficial geology layer for GCW is ‘extended’ northwestward from the beautiful work of RD Miller in Áak’w and T’aakú Aaní. It uses colorcodes from his unit-types, and is currently pretty coarse. Definitely a work in progress, that could benefit from a lot of ground-truthing by residents!